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 * Copyright (c) 1997, 2009, Oracle and/or its affiliates. All rights reserved.
 * ORACLE PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
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 */

package java.beans.beancontext;

import java.util.EventObject;

import java.beans.beancontext.BeanContext;

/**
 * <p>
 * <code>BeanContextEvent</code> is the abstract root event class
 * for all events emitted
 * from, and pertaining to the semantics of, a <code>BeanContext</code>.
 * This class introduces a mechanism to allow the propagation of
 * <code>BeanContextEvent</code> subclasses through a hierarchy of
 * <code>BeanContext</code>s. The <code>setPropagatedFrom()</code>
 * and <code>getPropagatedFrom()</code> methods allow a
 * <code>BeanContext</code> to identify itself as the source
 * of a propagated event.
 * </p>
 *
 * @author Laurence P. G. Cable
 * @see java.beans.beancontext.BeanContext
 * @since 1.2
 */

public abstract class BeanContextEvent extends EventObject {

  private static final long serialVersionUID = 7267998073569045052L;

  /**
   * Contruct a BeanContextEvent
   *
   * @param bc The BeanContext source
   */
  protected BeanContextEvent(BeanContext bc) {
    super(bc);
  }

  /**
   * Gets the <code>BeanContext</code> associated with this event.
   *
   * @return the <code>BeanContext</code> associated with this event.
   */
  public BeanContext getBeanContext() {
    return (BeanContext) getSource();
  }

  /**
   * Sets the <code>BeanContext</code> from which this event was propagated.
   *
   * @param bc the <code>BeanContext</code> from which this event was propagated
   */
  public synchronized void setPropagatedFrom(BeanContext bc) {
    propagatedFrom = bc;
  }

  /**
   * Gets the <code>BeanContext</code> from which this event was propagated.
   *
   * @return the <code>BeanContext</code> from which this event was propagated
   */
  public synchronized BeanContext getPropagatedFrom() {
    return propagatedFrom;
  }

  /**
   * Reports whether or not this event is
   * propagated from some other <code>BeanContext</code>.
   *
   * @return <code>true</code> if propagated, <code>false</code> if not
   */
  public synchronized boolean isPropagated() {
    return propagatedFrom != null;
  }

    /*
     * fields
     */

  /**
   * The <code>BeanContext</code> from which this event was propagated
   */
  protected BeanContext propagatedFrom;
}
